Meanwhile I implemented a little viewer (https://github.com/rochus-keller/Cedar/ ) and started to study the source code, but was very surprised that there doesn't seem to be any object orientation. I had a look at Lampson's Cedar language description some years ago and had the impression that it included OO support, but this was apparently not implemented. I'm particularly interested because Wirth created Oberon after his second stay at PARC where he was exposed to the Cedar language and environment, and Oberon has inheritance (and there are quite many similarities of his Oberon System UI with the Cedar UI).

The Cedar language version manifested in the now published source files (including the Solaris version by 1993) seems to be rather Mesa plus garbage collected structures implicitly "interiting" from ANY for late binding, but no general inheritance and apparently also no polymorphism.

Do you have some inside information about this?